Deployment of a Solar-Powered Field Camera for Monitoring Living Marine Resources

Monitoring of living marine resources in their natural habitats can be done with a solar-powered and computer-based field camera system designed and assembled using commercially available components. River herring are ecologically, and socioeconomically, significant to the North American Atlantic Coast. They are anadromous forage fish that return to inland freshwater ecosystems to spawn every spring and are a key component of the energy transfer between marine and freshwater ecosystems. River herring, as forage fishes, support many recreational and commercial fish species and the associated fisheries. River herring populations have declined compared to historic levels due to decades of habitat loss and degradation, overfishing, and as bycatch in other Atlantic fisheries. They have supported some of the oldest fisheries in North America, and to this day the Mashpee Wampanoag tribe relies on the river herring as a food source. The annual river herring spawning runs support local ecotourism and community connection to natural resources, despite a moratorium on harvest in the state of Massachusetts. Local and state fisheries managers, scientists, and conservation groups are collaborating to restore river herring habitats and populations, which are monitored with human observers and electronic counting systems. Additional methodologies for population estimation are needed to better understand population dynamics over time and between locations. A video surveillance system can economically observe and record the spawning migration for later review, archiving, or sharing/outreach. Solar-powered field cameras were installed in the Santuit River and the Coonamessett River on Cape Cod, Massachusetts, USA to monitor the river herring spawning populations. The cameras have infrared lights for nighttime recording, and the computer controlling it was set to record 24 hours per day; storing the footage locally in an external solid-state drive as (24) 1 hour-long videos. Video footage of the spawning migration can be reviewed by humans or paired with computer-based image recognition technologies. The “HelioCase” is a portable, solar-battery-powered, Raspberry Pi-based system that was developed by Bennett et al, 2023. The HelioCase is intended to be an economic and robust field computer system that can be easily customized to fit user needs, in this scenario it acts as a remote field camera for marine wildlife observation. Power is supplied by solar panels and is stored in a lightweight LiFePO4 battery. The Raspberry Pi acts as the camera controller unit and access point. The Raspberry Pi computer can utilize cellular or satellite networks for internet access and remote control; data transmission and camera control can be done remotely or locally. This deployment of the HelioCase system aims to improve population estimates through more complete monitoring of the annual spawning migration event, providing river herring monitoring coverage for the times of the day that human observers are not present. This paper discusses the construction of the HelioCase with commercially available components, and the deployment in two rivers on Cape Cod that support river herring populations. Consumer camera and computer technology is an accessible method for natural resource managers to monitor multiple points of interest and can promote more efficient and effective decision-making for sustaining valuable living marine resources.